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///M3 Forum The BMW E46 ///M3 is the M version E46 and puts out an amazing 333 HP and 262 lb-ft of torque at stock specs! There are an amazing amount of modifications for both the coupe and convertible models so read up and get started modifying your cars today!

Hey Guys,
New M3 owner here. When I took the car in for the pre-sale inspection, the DME threw (105) 69 Engine Temperature Signal Implausible (1x; Not
Present). I was told by the tech there that the thermostat needs to be replaced.
I took possession of the car today and even after driving 30 miles on the freeway, the temperature gauge needle stayed pegged in the middle. No sign of over-heating, is that possible with a stat failure
What do you guys think could be the problem? Any ideas on troubleshooting this?

The thermostat is designed to fail open. Not like domestic vehicles that fail closed. Your thermostat probably isn't the issue. There are 2 temp sensors that might be causing the issue. Check the connectors. Your error means it sees the temp as completely out of range when compared to the rest of the data that it's processing.

Temps all seem good to me. With a/c on they should go up and mine usually always runs dead center but tstat seems to be working if it changes temps up and down. Try running it with heater full blast and record numbers

Can I just clear the error code and forget about it? Do you guys know how to DIY clear the error?
Thanks for all your input.

I just looked over thread again. Doesnt seem like sensor cuz your temp guage is so near normal and dont think tstat cause car prob wouldnt get to normal temp on guage if open tstat.Should be able to use just about any obd2 scan tool to erase. Try take car for a good drive before you think its good for sure. Keep it revved around 4000 rpm in first or second so it doesnt get much wind( disconnect fan) see that tstat is opening or if it gets too hot. Could use laser temp gun on rad. Just some more tests if you want. Sounds good to me but just watch the guage and erase is prob good